The present paper proposes psychological ownership of IT (POIT) as a construct that can provide a much needed linkage between the IT implementation and IT acceptance research streams. To assess this idea, a research model was developed where POIT was hypothesized to mediate the influence of user participation on perceived usefulness (PU) and perceived ease of use (PEOU). This model was tested with questionnaire data collected from 91 physicians who were using a newly implemented clinical information system across a network of medical clinics. The results of partial least square analysis of the data indicated that POIT was a significant mediator of the influence of user participation on PU and PEOU, providing strong support for the research model.